Theoretically, it's 'infinite', but out in the real world, expect around 20~25dB loss from being completely cross-polarized. When I was doing commercial satellite work, if we could get 26~27dB we were happy, but this was with rigidly controlled satellites and commercial ground stations. Between linear and circular, expect about 3dB loss. Jim KQ6EA
--- On Fri, 9/19/08, Tim Tapio tim@timtapio.com wrote:
From: Tim Tapio tim@timtapio.com Subject: [amsat-bb] Polarity questions To: amsat-bb@amsat.org Date: Friday, September 19, 2008, 5:58 AM Hi,
How much signal reduction is there as the result of having the wrong circular polarization? I'm looking at M2 circular antennas for the 70cm downlink, it's another $200 for the switching to change polarity (woo hoo).
73 de Tim, K4SHF
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb